Inflatable mandrel



, MM AT'TY;

July 30, 1968 e. H. HISE ET AL INFLATABLE MANDREL Filed Dec. 27. 1966 INVENTORS GORDON H.HISE BY GERALD L.MAY

w mm w$ HI HHII. Q T |||\I||||||.)|| 1 @w i 2 Q .m Qm @m E: m @w United States Patent 3,394,902 INFLATABLE MANDREL Gordon H. I-lise, North Canton, and Gerald L. May,

Akron, Ohio, assignors to The B. F. Goodrich Company, New York, N.Y., a corporation of New York Filed Dec. 27, 1966, Ser. No. 604,836 1 Claim. (Cl. 242-72) ABSTRACT OF THE DISCLOSURE An inflata'ble mandrel having an inflatable tube circum-ferentially extending around the periphery of a mandrel core with two circumferential sealing elements on the inside wall of the tube, a supply port randomly spaced between .the sealing elements and a means for communicating air pressure through the mandrel core and into the tubes to inflate and radially expand the tube to provide a mandrel load bearing surface having a diameter substan tially greater than the diameter of the mandrel core.

This invention relates to inflatable mandrels and more particularly to an inflatable mandrel especially suitable for supporting winding tubes or cores on which webs of sheet material such as paper may be wound.

An inflatable mandrel generally consists of a rigid noninflatable member and an arrangement of inflatable elements on the rigid member which expand when inflated to grip the inner wall of the winding tube or core of a roll of webbing. In one inflata'ble mandrel design, the mandrel includes a rigid core or shaft having a plurality of axially spaced inflatable tubes circumferentially extending around the mandrel core.

A major disadvantage of the axially spaced tube mandrel is that normally each of the inflatable tubes must be individually supplied with air by means of suitable plumbing connections located in the interior of the mandrel core and when designing mandrels for winding rolls having very small diameters the space within the core of the mandrel does not permit the installation of plumbing. Moreover, as the requirements of mandrel length increases, it becomes more diflicult to connect the inflatable tubes at the center of the mandrel because there is no convenient access to this portion of the mandrel core and therefore present inflatable mandrel designs have definite length limitations. However, the inflatable mandrel of this invention does not require plumbing or fittings for each tube, and therefore it may be used in both small diameter and long length mandrel applications.

These former inflatable mandrels were prone to failure when the individual tube stems were damaged as a result of excess torquing between the tube and its rigid core. Inasmuch as there are noindividual tube fittings in the inflatable mandrel of this invention there can be no failure resulting from excess torquing. Actually, the inflatable tubes of this invention can circumferentially slip on its rigid core whenever the torque load is excessive and there will be no loss of pressure in the tubes or damage to the tubes.

According to this invention, an improved inflatable mandrel includes a mandrel core having a communication port with one end open to a pressure source and the other end open to the outside cylindrical wall of the core, an inflatable tube circumferentially extending about the periphery of the mandrel core, and two circumferential sealing elements axially spaced at the inside wall of the tube forming a sealed chamber between the inner wall of the tube and the outer periphery of the core so that air supplied to the communication port of the mandrel core may be communicated to the inflatable tubes which on inflation radially expand to provide a load-bearing mandrel 3,394,902 Patented July 30, 1968 surface having a diameter substantially greater than the diameter of the mandrel core.

The invention will be further described with reference to the accompanying drawings which show by way of example several inflatable mandrels designed according to and embodying the principles of this invention.

In the drawings:

FIG. 1 is a partial longitudinal sectional view of one form of the mandrel with the left half fully inflated supporting a roll of paper, and the right half in its uninflated condition;

FIG. 2 is a partial section of a modified inflatable mandrel construction in its uninflated condition; and

FIG. 3 is a partial section of a third alternate inflatable mandrel construction in its uninflated condition.

Referring to FIG. 1, the inflatable mandrel 10 includes a mandrel core or shaft 12 and four axially spaced inflatable tubes 14, 16, 18 and 20 circumferentially extending around the periphery of mandrel core 12. In FIG. 1, tubes 14 and 16 are shown in their fully inflated condition supporting a roll of paper 22 wound on a cardboard liner 24, and tubes 18 and 20 are shown in their deflated condition. The mandrel core 12 includes an axial bore 26 at one end and four intersecting radial bores 28, 30, 32 and 34. An inflation valve 36 is threaded in the open end of bore 26. This valve 36 is responsive to a source of air supply (not shown) to communicate a suitable air supply through bore 26 and into the four radial bores 28, 30, 32 and 34. These radial bores 28, 30, 32 and 34 communicate the air supply to the pressure receiving inner walls of the inflation tubes 14, 16, 18 and 20, respectively, as shown in FIG. 1.

The constructions of tubes 14, 16, 18 and 20 are similar and therefore only tube 20 will be described in detail. Tube 20 is preferably a fabric reinforced rubber tube which has a substantially flat cross section including an inner wall and a larger diameter outer Wall when in its deflated condition shown in FIG. 1. An inflation port 44 is centrally located in the inner wall of tube 20 and two rubber sealing beads 40 and 42 are molded to the inner wall of tube 20 on opposite sides of the inflation port 44. In FIG. 1, the sealing beads 40 and 42 of tube 20 seal an area between the outer periphery of core 12 and the inner wall of tube 20. Tube 20 is assembled on core 12 with the inflation port 44 in alignment with the opening of radial bore 34.

To inflate tube 20 air is supplied to valve 36 to be communicated through axial bore 26 and radial bore 34. This air will move from radial bore 34 to the sealed region between sealing beads 40 and 42 and from this region the air will be communicated through the inflation port 44 of tube 20 to inflate the tube.

In the inflatable mandrel 10 of FIG. 1, mandrel core 12 includes a circumferential manifold inflation groove 46 which cuts through the opening of radial port 34. This groove 46 is provided so that the air from radial bore 34 will move through this groove 46 until it communicates with inflation port 44 on tube 20. It is not absolutely necessary that the mandrel 10 have a groove 40. However, groove 46 is desirable because tube 20 can be positioned on mandrel 12 so that inflation port 44 is in the plane of groove 46, but it is not necessary to circumferentially align port 44 with radial bore 34. Therefore, installation is simplified and in the event of circumferential slipping of tube 20 on mandrel .12 the air has a convenient passage between radial port 34 and tube port 44 during either the inflation or deflation cycle of operation.

Another feature included in the mandrel 10 of FIG. 1 is a pair of grooves 48 and 50 which may be provided in mandrel 12 to permit a seating of the beads 40 and 42. These grooves 48 and 50* assure the lateral alignment of the inflation port 44 of tube 20 with respect to the radial port 34 during assembly and further prevent the lateral shifting of tube 20 on mandrel core 12 when mandrel is in use. However, it is important to note that tube may be installed on a smooth mandrel core 12 since the sealing beads 40 and 42 need only provide enough initial sealing force to assure that the air supply will initially pass into tube 20 through port 44. After the initial burst of air, and as the air fills tube 20, the pressure inside the tube 20 will act to force these beads 40 and 42 into even greater" sealing engagement against the periphery of core 12. Therefore, it is only necessary that the diameter and resiliency of these beads 40 and 42 be enough to resist the initial burst of air pressure.

When the mandrel 10 is in its deflated condition, the tubes 14, 16, 18 and 20 are substantially flat as illustrated by tubes 18 and 20 in the right half of mandrel 10 in FIG. 1. The uninfiated mandrel 10 presents a small diameter which may be readily inserted into the liner core 24 of roll 22. To engage the inside wall of liner core 24 to support paper roll 22 a suitable air supply is communicated to mandrel 10 at valve 36 which in turn communicates air through axial bore 26 and into each of the radial ports 28, 30, 32 and 34. The air in these radial ports communicates around four circumferential inflation grooves 46, 46 at the mouth of each of the radial ports and from these grooves 46, 46 air is communicated to the interiors of tubes 14, 16, .18 and 20 through an inflation port 44 on each of the tubes to fully inflate each of the tubes to the fully inflated or expanded condition shown typically by tubes 14 and 16 in the left half of the mandrel 10 in FIG. 1.

To remove the mandrel 10 from the paper roll liner 24, the air pressure is released and the air is reversely exhausted from each of the tubes through its inflation port 44, inflation groove 46 on mandrel core 12, its respective radial port and out through the valve 36 of axial bore 26.

FIG. 2 illustrates a second embodiment of the invention where the sealing elements of the inflatable mandrel 60 include a pair of O-rings 62 and 64 which seat in mating grooves 66 and 68 on the mandrel core 70. The inside diameter of inflatable tube 72 is designed so that the inner wall of tube 72 will bear against O-rings 62 and 64 to provide initial sealing of this region between tube 72 and mandrel core 70. After this initial sealing at O-rings 66 and 68, the increasing air pressure inside tube 72 will increase the seal at O-rings 66 and 63 and force the unsealed margins of the inner wall of tube 72 against the periphery of mandrel core 70 to maintain a pressure seal between tube 72 and core 70 whenever mandrel 60 is in an inflated condition.

Similarly, FIG. 3 illustrates another embodiment of the invention where the mandrel has a mandrel core 92 which includes a pair of circumferential ridges 94 and 96 located around the outside periphery of the mandrel core 92. The inside diameter of tube 98 is designed to bear against these ridges 94 and 96 to provide the desired initial seal at the region between the tube 98 and core 90.

It is to be understood that further modifications and adaptations may be made without departing from the spirit and scope of the invention as set forth in the appended claim.

We claim:

1. An inflatable mandrel for supporting a winding roll comprising a mandrel core having a diameter substantially less than the inside diameter of the winding roll to be supported; a plurality of axially spaced closed tubes extending circumferentially on said mandrel core, each of said tubes having an uninfiated outside diameter only slightly greater than the diameter of said mandrel core and an inflated outside diameter substantially greater than the diameter of said mandrel core, and at least one inflation port on the inside diameter of said tube; a pair of axially spaced bead members intermediate said mandrel core and the inside diameter of said closed tubes; an annular manifold groove on said mandrel core intermediate each pair of spaced bead members in axial alignment with said tube inflation port; and means for communicating an inflation medium from the interior of said mandrel core to each of said annular manifold grooves for inflation of said tubes to their inflated load bearing diameter.

References Cited UNITED STATES PATENTS 1,921,123 8/1933 Hermann 242-72 3,010,671 11/1961 Brown 242-72 2,298,626 l/ 1967 Friok et al. 242--72 FRANK J. COHEN, Primary Examiner.

NATHAN L. MlNTZ, Assistant Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,394,902 July 30, 1968 Gordon H. Hise et a1.

It is'certif ied that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

Column 2, line 59, "40" should read 46 Column 4, line 41, "Hermann" should read Herrmann line 43, "2 ,298 ,626" should read 3 ,298 ,626

Signed and sealed this 30th day of December 1969.

(SEAL) Attest:

M. Fletcher, Jr.

Attesting Officer Commissioner of Patents WILLIAM E. SCHUYLER, J11, 

